The present invention relates to stimulation systems, for example, spinal cord, peripheral, and deep-brain stimulation systems. A spinal cord stimulation system is an implantable pulse generating system used to provide electrical stimulation pulses from an electrode array placed epidurally or surgically near a patient's spine. An implanted pulse generator (IPG) may operate independently to provide the required electrical stimulation, or may interact with an external programmer, which delivers programming and/or control information and/or energy for the electrical stimulation, typically through a radio-frequency (RF) or other wireless signal.
Spinal cord stimulation (SCS) is a well-accepted clinical method for reducing pain in certain populations of patients. SCS systems typically include an implanted device, lead wires, and electrodes connected to the lead wires. The implanted device receives signals from an external programmer, and transmits corresponding electrical pulses that are delivered to the spinal cord (or other tissue) through the electrodes which are implanted along the dura of the spinal cord. In a typical situation, the attached lead wires exit the epidural space and are tunneled around the torso of the patient to a subcutaneous pocket where the device is implanted.
Spinal cord and other stimulation systems are known in the art. For example, in U.S. Pat. No. 3,646,940, there is disclosed an implantable electronic stimulator that provides timed, sequenced electrical impulses to a plurality of electrodes so that only one electrode has a voltage applied to it at any given time. Thus, the electrical stimuli provided by the apparatus taught in the '940 patent comprise sequential, or non-overlapping, stimuli.
In U.S. Pat. No. 3,724,467, an electrode implant is disclosed for the neurostimulation of the spinal cord. A relatively thin and flexible strip of physiologically inert plastic is provided with a plurality of electrodes formed thereon. The electrodes are connected by leads to an RF receiver, which is also implanted, and which is controlled by an external controller. The implanted RF receiver has no power storage means for generating electrical stimulations and must be coupled to the external controller in order for neurostimulation to occur.
In U.S. Pat. No. 3,822,708, another type of electrical spinal cord stimulating device is shown. The device has five aligned electrodes which are positioned longitudinally on the spinal cord and transversely to the nerves entering the spinal cord. Current pulses applied to the electrodes are said to block sensed intractable pain, while allowing passage of other sensations. The stimulation pulses applied to the electrodes are approximately 250 microseconds in width with a repetition rate of 5 to 200 pulses per second. A patient-operable switch allows the patient to change which electrodes are activated, i.e., which electrodes receive the current stimulus, so that the area between the activated electrodes on the spinal cord can be adjusted, as required, to better block the pain.
Other representative patents that show spinal cord stimulation systems or electrodes include U.S. Pat. Nos. 4,338,945; 4,379,462; 5,121,754; 5,417,719, 5,501,703, and 6,516,227. All of the patents noted above are hereby incorporated by reference.
A typical IPG is self contained, having a multi-year battery pack and a single treatment program, and is generally programmed during or immediately following implantation in the patient's body.
Other SCS systems have no implanted power source, but receive power and programming and/or control information from an external transmitter. These systems will convert the RF signals from the transmitter to provide power to the implanted receiver, and use the RF programming information to determine the intensity, location, and duration of the electrical pulses delivered to the electrodes.
There is a significant programming limitation with known SCS systems. In a typical IPG, the patient's program is installed during implantation, and the patient must visit a doctor to have any programming changes made.
During this initial or follow-up programming session, there is currently no easy way to develop and calibrate treatment protocols. Current methods require an IPG program to be manually configured, downloaded, and then tested on the patient. If the program is not optimal, the entire process must be repeated.
In U.S. Pat. No. 6,393,325, also incorporated by reference, a system for programming an IPG is shown. In this system, a user can select between multiple individual stimulation settings. Here, while a stimulation is continually applied, the user can manually switch from one electrode combination to another. Also, while a stimulation is continually applied, the user can adjust pulse width and frequency, and can adjust the amplitude of the stimulation current. Finally, while a stimulation is continually applied, the user can use directional arrows to change the electrode configuration in an attempt to “direct” the stimulation to affect a particular area of the body. In each of these cases, only one stimulation setting/electrode configuration appears to be used at a time, so the user is limited to treating “simple” pain, in only one area of the body.
There is, therefore, a need in the art for an improved system, process and device for improved interactive programming for IPGs.